Consider the three triangles of circles shown each pointing upward It is easy to see that the triangle of three circles on the left can be inverted that is made to point downward by moving one circle Use the triangles of circles to complete parts a through c below a What is the smallest number of circles that must be moved in order to invert the 6 circle triangle 2 circles b Show that the 10 circle triangle can be inverted by moving 3 circles O A B